1. Field of the Invention
The invention relates to a method for operating a fuel evaporation retention system in a hybrid vehicle or in a motor vehicle with automatic start/stop, with a fuel tank and with an activated charcoal filter container equipped with an activated charcoal filter and with a tank venting valve that is activated by means of a control apparatus so that the activated charcoal filter container is scavenged while the motor vehicle is in operation.
2. Description of the Related Art
U.S. Pat. No. 6,679,214 B2, U.S. Pat. No. 6,557,534 B2, JP 09184436 A, JP 2007210536 A and JP 2005023881 A disclose various measures for controlling fuel evaporation in the fuel tank of motor vehicles. For example, U.S. Pat. No. 6,679,214 B2 proposes holding the internal pressure in the fuel tank at a preselected pressure level while the internal combustion engine is being operated. A stopping of the internal combustion engine is to be prohibited when the internal fuel tank pressure overshoots the preselected pressure level. U.S. Pat. No. 6,557,534 B2 determines the pressure in the fuel tank of a vehicle that has a hybrid drive and compares the pressure with a balanceable pressure stage. The comparative values are used for regulating a throttle valve plate.
The object of the invention is to prevent an undesirable flooding or breaching of the activated charcoal filter during the operation of a hybrid vehicle or of a motor vehicle with automatic start/stop.